1. Field of the Invention
This invention relates, generally, to underwater dock lights.
2. Background Art
The light emitting unit in many conventional underwater lights are incandescent bulbs that are not energy efficient. Metal hydride lighting systems require the use of bulky transformers that are also not energy efficient compared to compact fluorescent lighting (CFL) or high intensity light emitting diode (LED) systems. Transformers make the assembly more costly and are unsightly. Incandescent, metal hydride, and CFL bulbs use hazardous high voltage A/C current. When these bulbs are used in underwater lights, the use of a ground fault circuit interrupt (GFCI) is recommended for safe operation. GFCI's add additional cost to an underwater light system. LED systems can operate with non-hazardous, low voltage D/C current which is a much safer alternative to the prior art A/C systems. Moreover, incandescent bulbs, CFL bulbs, and metal hydride bulbs have a short life expectancy in comparison to LEDs.
High intensity LEDs used in light systems produce concentrated heat at each LED. Although an underwater light assembly has a relatively stable external temperature due to submersion, without a way of dissipating the heat from a concentrated point of each LED, the high intensity LED will overheat and become damaged.
There are several challenges to overcome with using high intensity LEDs in an underwater light system. One challenge being the need for the LED to be in contact with a heat sink capable of sufficiently transferring heat. The problem with a heat sink in an underwater light is determining how to cool the heat sink. Thus, there is a need for an improved method of cooling LEDs inside an underwater light.
Currently, most prior art underwater lights on the market operate in about ten feet or less of water. These underwater lights have a light emission that is configured to beam away from the light fixture housing, resulting in the light source emitting a beam of light. In shallow water, the light beaming upward results in an underwater light having a small diameter of light being illuminated. Thus, there is a need for an improved, underwater light that directs the light not only upward, but radiating outward to produce a large diameter of light being illuminated in shallow water.
Prior art underwater lights are not energy efficient compared to the diameter of light they produce. Thus, there is a need for an underwater light that produces a brighter light and a larger diameter of light in a body of water. This is more desirable to an observer and attracts more marine life to the site. More particularly, a brighter light is more effective at penetrating murky water.
Prior art underwater lights illuminate the surrounding water a single color. Thus, there is a need for an improved underwater light that illuminates the surrounding water with multiple colors simultaneously.
Prior art underwater lights incorporate a compression nut to attempt to seal an electrical cord to a light housing. However, the constant underwater tugging motion and temperature variations result in expansion, contraction, and fatigue of the electrical cord against the compression nut. This constant tugging from the water movement and temperature variations results in a high failure rate of sealing an electrical cord to a light housing, allowing water to enter the light and damage the electrical components.
Some prior art underwater lights are designed to accept an electrical cord through an opening penetrating the light housing. Liquid resin is applied to the light housing's opening to create a seal. The problem with the prior art light housing is that as the resin hardens to a solid state, it begins to shrink and pull away from the inner perimeter wall of the light housing opening.
More particularly, due to the liquid resin shrinking and pulling away from the inner perimeter wall of the light housing opening, the underwater light will leak water in a gap formed between the inner perimeter wall opening of the light housing and the hardened resin. When water leaks into an underwater light, the integrity of the unit is compromised and the unit fails. Thus, there is a need for an improved sealing structure that produces a permanent, water-tight seal.
However, in view of the prior art considered as a whole at the time the present invention was made; it was not obvious to those of ordinary skill in the pertinent art how the identified needs could be fulfilled.